The -I option specifies the Ethernet interface to use. Under Linux, it is typically eth0 or eth1. The interface should be “up” before you start pppoe-discovery, but should not be configured to have an IP address. The default interface is eth0.

Causes pppoe-discovery to use the Host-Uniq tag in its discovery packets. This lets you run multiple instances of pppoe-discovery and/or pppoe without having their discovery packets interfere with one another. You must supply this option to all instances that you intend to run simultaneously.

Specifies the desired service name. pppoe-discovery will only accept access concentrators which can provide the specified service. In most cases, you should not specify this option. Use it only if you know that there are multiple access concentrators or know that you need a specific service name.

Specifies the desired access concentrator name. pppoe-discovery will only accept the specified access concentrator. In most cases, you should not specify this option. Use it only if you know that there are multiple access concentrators. If both the -S and -C options are specified, they must both match.